PI=3.14
r=float(input("请输入圆的半径： "))
def area(s):
    return PI*r*r
def volume(v):
    return 4/3*PI*r*r*r
def main():
    print('圆的面积=',area(r))
    print('球的体积=',volume(r))
if __name__ == '__main__' :
    main()
